Facebook said on Friday its accounting chief is leaving the company and that it will undertake its first-ever stock buyback program, worth $6 billion.

Chief Accounting Officer Jas Athwal — a nine-year veteran of Facebook, who was promoted to his current role in 2013 — is “retiring,” a source close to the company said, adding that Facebook has begun an external search to find a replacement.

Asked Friday about Athwal’s age, Facebook officials declined to comment. His Wikipedia page has him at 53.

The share-buyback program, slated to begin in the first quarter, comes as Facebook’s stock has taken a beating lately.